<template>
  <div class="app">
    <h1>app---{{ msg }}</h1>
    <input
      type="text"
      v-model="msg"
    />
    <Child v-model:msg="msg"></Child>
  </div>
</template>
<script setup>
import { ref } from 'vue'
import Child from './Child.vue'
const msg = ref('父组件的数据')
</script>
<style
  lang="scss"
  scoped
></style>
